Feedinakdo tommasi



P. TOMMASI. Electric-Lamp.

Patented May 11,1880.

N PETERSv PNOTO-LITNOGRAPHER, Wnsmnarom D C.

UNITED STATES PATENT OFFICE.

FERDINANDO TOMMASI, OF PARIS, FRANCE.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 227,596, dated May 11, 1880.

Application filed January 10, 1880.

To all whom it may concern Be it known that I, FERDINANDO TOMMASI, of Paris, in the Republic of France, have invented certain new and useful Improvements in Electric Lamps; and I hereby declare that the following is a description of the same, reference being had to the accompanying drawmgs.

This invention relates to electric lamps with multiple carbons, in which the current is distributed alternately and automatically through different carbons which burn successively, and which, each only burning for a short time, cannot heat the quicksilver in the tubes which contain them, thereby avoiding the generation of mercurial vapors, which often presents such grave inconveniences. The lamps of my system are, besides, combined in such manner as not to project any shadow on the points which they ought to illuminate, and while certain types are more especially intended to illuminate laterally, others, on the contrary, are expressly combined with a view to concentrate all the luminous rays downward, and are consequently adapted to the lighting of work-tables, tables for playing, &c. The carbons, of which there may be any number, are plunged into convergent tubes containing quicksilver, which, being heavier, constantly pushes them upward as they are consumed in such manner as to keep them in constant contact with a central abutment-piece or button common to all of them.

Figure 1 in the drawings is an elevation, partly in section, of an electric lamp containing my improvements and mounted upon a foot or support. Fig. 2 is a horizontal section of the same. Fig. 3 is a vertical section of the lower part of one of the tubes at right angles to the section shown in Fig. 2.

As may be seen in the drawings, the carbons a a a a a a, of which there are six in the lamp, represented in the form of sticks or pencils, are contained in tubes 1) b b b b b, which are filled with quicksilver, and which are turned up at their bottoms, as shown in Fig. 3, to retain therein a quantity of air, the pressure of which maintains a constant level of the quicksilver in the tubes during the burning away of the carbon. These tubes are mounted upon a common platform, 0, resting upon fixed supports cl, secured on a suitable base. This platform is covered with a plate, 0, of hard rubber or other insulating material, which insulates the tubes and their carbons. The said platform also supports a central rod or post,f, on the upperpart of which is loosely fitted a carbon collar or button, g, which is constantly pressed upward by a spiral spring, f, surrounding the said post, and which is retained by a nut, h, screwed onto the threaded upper end of the said post.

The tubes and their contained carbons converge upwardly toward the collar or button g, which constitutes a central abutment-piece, into contact with which the carbons are severally pressed by the quicksilver in their several tubes.

On the lower part and in front of the supports d is the mechanism for the alternative distribution of the current. The motor of this mechanism is represented as a toothed sprin barrel, i (shown in dotted outline in Fig. 1,) containing a spring mounted upon an arbor, i. The teeth on this barrel gear with a pinion,j, upon the arbor of which is mounted a wheel, 7t, gearing with a second pinion,j, which is geared by a train of acceleratirig-gearing, It It 7t j j, with a flier, m, which is mounted upon the arbor of thelast pinion, j, which has thus imparted to it a sufficient velocity of rotation to regulate the movement of the motor-arbor 1 This arbor t'passes through a dial, a, formed of a plate of hard rubber or other insulating material, on the face of which there are secured projecting metallic segments 0 0 0 0 0 0 corresponding in number with the carbons a a c a a a. ing in opposite directions and electrically insulated from each other, are mounted upon the said arbor i, and in turning with the latter these pointers rub upon the two diametrically-opposed metallic segments 0 0 0 0" 0" 0. Each of the said segments carries a stud or binding-screw, 1', which forms the connection for one of several wires, 8 s s s s 8, each of which forms a conductor between one of the said segments and one of the tubes 1) b I) l) b b and its contained carbon. The screws 1' are numbered from 1 to 6.

Two pointers, p q, point- The dial ncarries,besides, two concentric insulated metal rings, t a, which project therefrom equally with the segments, and which communicate, respectively, with two bindingscrews, 0 w, which are connected by wires with the studs or binding-screws m 3 which are fixed upon the base, and through which the current enters and leaves the lamp.

The pointers 1) q, secured upon the arbor i in front of the dial, are arrangedin such manner that the first, 1), touches the outer metallic ring, 15, without touching the inner ring, a, and that the second, (1,011 the contrary, only touches the inner ring, a.

In order to make the above'described arrangement more intelligible, the plan, Fig. 2, represents the two pointers horizontal and touching, respectively, the segments 0 and 0 Fig. 1 represents, on the contrary, the two pointers vertical, and it may be seen that their width is sufficient that each, before leaving one of the segments, may touch the next one. In this manner, as will be seen farther on,

there cannot be any interruption in the combustion of the lamp.

It results from the means which I havejust above described that if, for example, the cur rent enters into the apparatus by the stud .r, it goes to the exterior ring, if, of the dial, passes to the first pointer, 9, Fig. 2, and to the segment 0 which the said pointer touches, passes thence up by the wire 8 to the carbon a and traverses the collar g, which serves as a conductor. It then descends by the carbon c to the wire 8 and to the segment 0 passes into the second pointer, q, thence to the interior ring, a, with which it is in contact, and thence to the stud y, whence it passes out.

It will be observed that the converging carbons are arranged in pairs, arranged opposite each other, and that each pair of carbons are in a branch circuit which is ordinarily severed, and that the pointers p q, in their revolution, connect the two severed parts of each branch circuit successively.

It will be seen, then, that in this case the light flashes between two diametrically-opposed carbons, a? and a, which avoids all projection of shadow. Moreover, the pointers,in turning, pass successively over all' the seg ments, always touching at the same time two diametrically-opposite segments, and causing the current to pass through the corresponding carbons, of which the incandescence produces the light.

it may be understood that it is easy to produce the burning of only one carbon pencil at a time when necessary for any reason. It suflices for this to detach one of the pointers, 1) q, leaving the connections in the same manner between the segments and the carbons, and putting the collar 9 in communication with the set-screw z or 2, by which the current passes out. In this case the light is produced successively and alternately between each-of the carbons and the collar 1.

It may he, moreover, understood that the mechanism for distribution of the current, instead of being placed in the foot or base of the lamp, may be placed in the upper part, above the collar or button g. In this case the base and the central post, f, may be dispensed with, and the lamp may be suspended. Dispensing with the center post permits the illumination with a single carbon pencil, as

just above described, without casting a shadow in either direction.

The dispensing with all lateral support, which is one of the distinctive characteristics of my lamps, is very important to the avoidance of shadows.

It may be further understood that the mechanism for the distribution of the current, instead of being placed on the lamp itself, as in the two cases which I have described, may be placed at a greater or less distance, with a suitable arrangement of conducting-wires.

This last-mentioned arrangement is, above all, convenient in the case of submarine lamps established on my system, when it may be desirable to keep the distributing mechanism on shore or afloat while the lamp is lowered into the water.

I claim 1. The combination, in an electric-lighting apparatus, of a supporting frame-work, a rod projecting vertically therefrom, a carbon button or abutment arranged near the upper end of said rod, a spring coiled upon said rod to hold said button or abutment in an elevated position, a nut for movingsaid button or abutment downwardly against said spring, and a series of carbons arranged in cases supported upon said frame-work and upwardly converging against the under side of said button or abutment, substantially as specified.

2. The combination, in an electric-lighting apparatus, of a supporting frame-work, a rod projecting vertically therefrom, a carbon button or abutment arranged near the upper end of said rod, a spring coiled upon said rod to hold said button or abutment in an elevated position, a nut for adjusting said button or abutment downwardly against said spring, and a series of carbons upwardly converging against the under side of said button or abutment, and cases containing quicksilver for supporting said carbons and keeping them in contact with said carbon button or abutment, and supported upon said frame-work, substantially as specified.

3. The combination, in an electric-lighting apparatus, of a central carbon button or abutment, a series of carbons upwardly converging toward said central carbon button or abut ment and arranged in pairs, each pair of carbons being connected by a severed branch circuit, and rotary pointers or devices, which IIO IIS

in their rotation connect the two severed por- 0 0 850., and rings t u, the rotating pointers tions of each branch circuit successively, sub- 19 q, and mechanism for producingthe rotation 10 stantially as and for the purpose specified. of the said pointers, substantially as herein 4. The combination, with the central butdescribed. 5 ton or abutment-piece of carbon and the se- FERDINANDO TOMMASI.

ries of carbon pencils abutting against the Witnesses: same, of the current-changing apparatus con- J. A. DI BROAM,

sisting of the dial n, provided with segments \POYZO DI BORGO. 

